1. Field of the Invention
The present inventions relates generally to gas panels and fluid delivery systems, and more specifically to a mounting panel in a fluid delivery system.
2. Description of the Background Art
High purity gas delivery systems, like those used in semiconductor manufacturing or other tightly controlled processes, typically use a source of high purity gas that is distributed and controlled through a series of gas distribution and control components, such as a mass flow controller, one or more pressure sensors and/or regulators, one or more filters or purifiers, and shutoff valves. In semiconductor processing, a series-connected set of such components is usually referred to as a “gas stick” or “gas channel.” The components used and their particular configuration in a gas stick can vary depending upon design and application.
In a typical semiconductor processing arrangement, multiple gas sources are connected to the chamber through multiple gas sticks, which are typically mounted on blocks, a frame, or a panel to create a fluid delivery system often referred to as a “gas panel.”
In creating gas panels, different methods of connecting the gas sticks and of mounting them have been developed. FIG. 1 illustrates a prior art gas panel 100 made up of hundreds of discrete components, such as valves 102, filters 104, flow regulators 106, pressure regulators 107, pressure transducer 109, and connections 108, which are connected together by tens, or hundreds, of feet of tubing 110.
As individual components in gas panels shrank in size, different methods of connecting the gas sticks were developed, with the aim of reducing the size and cost of manufacturing of the gas panel. Two such connection methods are described in U.S. Pat. Nos. 5,836,355, and 6,186,177.
FIG. 2, which is from U.S. Pat. No. 5,836,355 (the “'355 patent”), depicts a gas panel 200 that includes base blocks 202, manifold blocks 204, and various components 206. A significant cost of the fluid delivery system is the cost of the manifold or mounting panel on which the individual control and sensing components are mounted. In the '355 system, the mounting panel is comprised of interconnected, modular mounting blocks. Each individual component comprises at least one mounting block, with mass flow controllers requiring two. Moreover, in the system of the '355 patent, the fluid channels, which are built by connecting multiple mounting blocks, run only in two straight-line directions, which limits the flexibility in laying out the fluid channels. In addition, each different direction requires a separate layer of mounting blocks. Because of such limited flexibility and the number of mounting blocks required, the size of fluid delivery system in the '355 patent is typically quite large, rendering the cost of manufacturing such system expensive. Also, the large physical size prevents locating the fluid delivery system in close proximity to the reaction chamber to which it is supplying fluids. This results in slower response times for switching gases and in other deleterious effects associated with large dead volumes, not the least of which is a decrease in productivity.
U.S. Pat. No. 6,186,177 discloses a simplified version of the modular mounting block concept. Specifically, it discloses using a single mounting block for each gas stick, where the flow channels for the gas stick are formed in the mounting block. However, because each mounting block accommodates only one gas stick, multiple mounting blocks must be used to connect multiple gas sticks together, as illustrated in FIG. 7 of the patent. Furthermore, the flow channels in each mounting block run in only one direction, which means that connecting multiple gas sticks together appears to require additional mounting blocks with channels running in substantially perpendicular directions to those of each gas stick. Therefore, although mounting blocks of the '177 patent may provide some advantages over those described in the '355 patent, they still have many of the same size and cost disadvantages.
Therefore, there is a desire for a smaller and more cost-effective fluid delivery system, especially a smaller and more cost-effective mounting panel for such system that enables multiple gas sticks or fluid channels to be connected together.
Moreover, there is also a need for an integrated, reduced-cost mounting panel that enables channels to be routed in three dimensions (i.e., the x, y, and z axis in a Cartesian Coordinate system). Multilayered structure that enable three dimensional routing of electric signals have been used for many years in the integrated circuit, printed circuit board, and hybrid package industries. A cost-effective solution analogous to the electrical delivery system has not been applied to gas panels or fluid delivery panels because of material and manufacturing limitations. Specifically, the low levels of contamination mandated by high purity processes, such as those encountered in the semiconductor, pharmaceutical, or optical fiber industry, severely restrict the materials which can be employed as well as the fabrication techniques (for example, welding panel components together often introduces sites for corrosion or particle generation).